The date set for the first legal Valencian Community Day was 9 October 1977, and in the run-up parties across Alicante were coordinating to put up posters. On the night of the 6th, four members of a group organised by the Communist Movement of the Valencian Country were at work in the Plaza de Los Luceros. They were young, some of them very young: Llum Quinonero, twenty-four; Miquel Grau, twenty-two, a native of Rafal; Juan Angel Torrerosa, nineteen; and Javier Alvarez, just fourteen years old. Pasting up notices for a regional holiday was, by any measure, an ordinary and lawful thing to be doing on a warm October night.

Above them lived Miguel Angel Panadero Sandoval, a militant of the far-right party New Force. From his balcony he threw a brick, and it hit Grau squarely on the head, leaving him in a coma. A passing driver helped get him to hospital, where he was admitted; on 16 October, ten days after the blow, Miquel Grau died of his injuries. He had survived a dictatorship only to be killed, at twenty-two, by a man who could not abide the sight of a Valencian flag going up on a wall. In the tense, uncertain years of Spain's transition to democracy, the violence did not all come from the state or the underground - some of it came from a window overhead.

The grief was enormous and it was public. Eighteen political parties and trade unions organised Grau's funeral at the church of San Martin in Valencia, and by the account of the newspaper El Pais somewhere between seven and ten thousand people came, filling the church and the streets around it. A fellow militant read a eulogy over the coffin of a man most of the crowd had never met. The following year the band Al Tall set his memory to music with the Catalan song A Miquel assasinaren - Miquel was murdered - so that his name would travel further than the square where he fell.

Panadero turned himself in to the police that same October. His trial drew Grau's family and left-wing militants on one side and a crowd of far-right sympathisers on the other, with prosecutions brought by the state, by the family, and collectively by a coalition of parties represented by the lawyer Juan Maria Bandres. He was sentenced to twelve years. In May 1979 the justice minister of the Suarez government, Inigo Cavero, granted a partial pardon that cut the term, and Panadero walked free in 1982. For decades that was where the story rested. Then, in 2015, the city acted: a plaque was set at the exact spot in the Plaza de Los Luceros, Grau was given a posthumous Gold Medal of the City and a street bearing his name, and the measure passed with the support of every party on the council - a late, unanimous act of memory for a young man killed for putting up a poster. Today a passer-by crossing the busy plaza can stand on the exact stones where he fell, and read the name the city took nearly four decades to inscribe there.